I have thought about to turn off the device before the full cycle finished. I thought about to add a power switch but that wasn't very attractive to me.

A couple days ago, I suddenly got a good idea to utilize the Region Detection pin6. Once the program detects the region from the level of pin 6 (float (internal pull-up): US, pull-down: EU), it is not used until all the code pulsing is finished. So, in US mode for example, after it started pulsing and when you want to stop it, forcing the pin6 to ground will exit the do loop in software and the device will go sleep. I tested both US and EU mode with modified code and worked fine. This way, you can save battery.